This invention concerns sleeving for encasing and protecting elongated substrates such as wiring harnesses and for reducing rattle noise from such substrates when they are used in a high vibration environment.
Elongated substrates, such as wiring harnesses, fluid conduits, such as brake lines and fuel lines, and optical fiber bundles are often used in automotive, aerospace and marine environments where they are subjected to significant ambient vibration. In automotive applications, wiring harnesses in particular are pernicious sources of unwanted xe2x80x9crattle noisexe2x80x9d due to their propensity to resonate in response to structure borne vibration caused by engine operation or irregularities of the road surface over which the vehicle is passing. Wiring harnesses typically extend substantially throughout the vehicle""s passenger compartment where they distribute power and control signals from the engine compartment to the dashboard instruments, interior lights, radio, speakers, electric windows, electric door locks, the window defogging element and on to the trunk to power the tail lights and often an electric fuel pump which may be positioned in the fuel tank. Although the harness is intermittently attached to the vehicle structure, the lengths of the harness between attachment points will often resonate and rattle against the structure in response to relatively low-frequency vibrations within the range of human hearing and provide a source of noise, which is both annoying and a cause of concern to the vehicle occupants. Aside from the noise annoyance, vibration of wiring harnesses will cause fatigue failures of the wiring, solder joints or mechanical connectors, leading to electrical malfunctions such as short circuits which could result in a vehicle fire. The failure due to vibration and fatigue of other elongate substrates, such as fuel lines or brake lines, also has catastrophic potential. There is clearly a need for a device which will help damp vibration of elongated substrates and thereby reduce sympathetic vibration of the substrates and its resultant rattle noise and associated fatigue failures.
The invention concerns a damped sleeve adapted to receive and protect elongated substrates. The sleeve comprises a flexible, resilient, elongated tubular support layer surrounding and defining an interior space adapted to receive the substrates. The support layer has a pair of edges positioned adjacent to one another and extending lengthwise along it, the edges defining a longitudinal slit in the support layer providing access to the interior space. A damping layer is attached to the support layer along the edges and substantially covers the outer surface of the support layer. The damping layer comprises an energy absorbing material, preferably a fibrous, non-woven felt.
The felt damping layer extends radially inwardly into the slit to substantially overlap one of the edges. The other of the edges comprises a plurality of hooks extending therefrom. The hooks are removably engageable with the felt to fasten the edges together in the manner of a hook-and-loop fastener, thereby closing the slit, the slit being manually openable by disengaging the hooks from the felt.
It is an object of the invention to provide a sleeve for protecting elongated substrates.
It is another object of the invention to provide a sleeve which damps vibration.
It is again another object of the invention to provide a sleeve which is easily recycled.
These and other objects and advantages of the invention will become apparent upon consideration of the following drawings and detailed description of preferred embodiments.